I loved living in DC, but most of the engineering roles were low pay and old tech. The biggest DC tech employers are government contractors that charge for butts in seats so talking about the volume of jobs in DC doesn't mean much.
Or alternatively, high pay and old tech working for military contractors in roles that require security clearance. In some cases tech employers must pay a premium to get someone to perform extraordinarily tedious work.
Hopefully Amazon's HQ2 will improve things.